1. Field of the Invention
This invention generally relates to digital communications and, more particularly, to a system for efficiently distributing electrical communications signals, converted from optical network communications, via a ring of optical network units (ONUs).
2. Description of the Related Art
FIG. 1 is a schematic block diagram depicting a “triple play” system for distributing optical communication signals to a customer premise (prior art). A optical line terminal (ONT) broadcasts a ITU-T G.984.3 PON (GPON) optical signal out to many ONUs, which are typically outside units, or to many optical network terminals (ONTs), which are typically indoor units. The ONUs (ONTs) convert the GPON optical signal into video, telephone, and Ethernet electrical signals for use in the customer premise. The responses back from the various ONUs (ONTs) are converted to a GPON optical signal and time division multiplexed (TDM) back to the OLT. A typical single-family unit (SFU) may have four Ethernet ports.
Additional issues are presented when an OLT is interfaced with a multi-dwelling unit (MDU), such as an apartment building. Currently, there are two methods of interfacing an OLT to an MDU. One option is place an ONU in each apartment, and run optical fiber to each ONU. This option is hardware expensive, because multiple copies of the optic fiber must be run in parallel to each ONU. Alternately, a single ONU is assigned to the MDU. However, the ONU must have a network processor and Ethernet switch to bring out multiple ports. This option is software expensive, because software must be written to configure the network processor and Ethernet switch. Further, a policing function must be enabled to guarantee each user a Service Level Agreement (SLA) that includes some measure of privacy protection.
It would be advantageous if an MDU could be interfaced to an OLT GPON optical signal with a minimum expenditure of software and hardware assets, and development costs.